I'm glad to hear you are seeing an improvement! The current implementation is still racy as mentioned in Comment #22. I did a search of the logs I downloaded, and I believe this one shows that the mount_partition() race isn't just theoretical:
https://autopkgtest.ubuntu.com/results/autopkgtest- mantic/mantic/amd64/l/livecd-rootfs/20230928_132941_a6800@/log.gz So my suggestion is that we: 1) wait for systemd 255.3 to be merged in noble to fix the issue w/ `udevadm lock` 2) convert livecd-rootfs to use udevadm lock in noble, addressing the remaining known races. 3) backport `udevadm lock` to jammy (likely as a low-priority SRU) 4) backport the`udevadm lock` support to livecd-rootfs I realize that'll take some time, so if you want to SRU the partial fix as a stop-gap, feel free. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2045586 Title: livecd-rootfs uses losetup -P for theoretically reliable/synchronous partition setup but it's not reliable Status in linux package in Ubuntu: New Status in livecd-rootfs package in Ubuntu: Fix Released Status in util-linux package in Ubuntu: New Status in linux source package in Jammy: New Status in livecd-rootfs source package in Jammy: New Status in util-linux source package in Jammy: New Status in linux source package in Mantic: New Status in livecd-rootfs source package in Mantic: New Status in util-linux source package in Mantic: New Status in linux source package in Noble: New Status in livecd-rootfs source package in Noble: Fix Released Status in util-linux source package in Noble: New Bug description: In mantic, we migrated livecd-rootfs to use losetup -P instead of kpartx, with the expectation that this would give us a reliable, race- free way of loop-mounting partitions from a disk image during image build. In noble, we are finding that it is no longer reliable, and in fact fails rather often. It is most noticeable with riscv64 builds, which is the architecture where we most frequently ran into problems before with kpartx. The first riscv64+generic build in noble where the expected loop partition device is not available is https://launchpad.net/~ubuntu- cdimage/+livefs/ubuntu/noble/cpc/+build/531790 The failure is however not unique to riscv64, and the autopkgtest for the latest version of livecd-rootfs (24.04.7) - an update that specifically tries to add more debugging code for this scenario - has also failed on ppc64el. https://autopkgtest.ubuntu.com/packages/l/livecd- rootfs/noble/ppc64el The first failure happened on November 16. While there has been an update to the util-linux package in noble, this did not land until November 23. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2045586/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
